Ultra-accelerated natural sunlight exposure testing facilities

ABSTRACT

A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in chamber means that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100× of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

[0001] This invention is a division of U.S. application Ser. No.09/521,731 filed Mar. 9, 2000, which is a continuation-in-part of U.S.application Ser. No. 09/006,746 filed Jan. 13, 1998.

CONTRACTUAL ORIGIN OF THE INVENTION

[0002] The United States Government has rights in this inventionpursuant to Contract No. DE-AC36-83CH10093 between the United StatesDepartment of Energy and the Midwest Research Institute.

BACKGROUND

[0003] 1. Field of the Invention

[0004] The invention relates to apparatus for subjecting materials toaccelerated irradiance exposure factors that permit about a year's worthof representative weathering to be accumulated in a period from about 3to about 10 days, under controlled weathering conditions that includeseveral concurrent levels of temperature and/or relative humidity atvery high levels of natural sunlight.

[0005] In the invention process, a solar concentrator [which may includea High Flux Solar Furnace (HFSF) and an Irradiance Redistribution Guide(IRG)] is used to obtain elevated levels (25-100×) of concentratedsunlight for accelerated testing of material samples. When an IRG isused, it provides the capability of being able to modify (redistribute)the Gaussian-shaped beam from the HFSF into a more uniform profile on asample exposure plane.

[0006] Also encompassed in the invention process for obtainingultra-accelerated natural sunlight exposure testing is the use ofreflective apparatus such as multi-step and multi-faceted concentratorsand refractive apparatus such as Fresnel lens concentrators, holographicconcentrators, 2D or 3D micro lens arrays, and an array of Fresnel lensfacets to obtain elevated levels (25-100×) of concentrated sunlight foraccelerated natural sunlight testing of material samples.

[0007] By adequately controlling sample temperatures and demonstratingthat reciprocity relationships are obeyed (i.e., the level of appliedaccelerated stresses does not change the failure/degradation mechanism),this novel capability allows materials to be subjected to acceleratedirradiance exposure factors of 25-100×, thereby permitting a year'sworth of representative weathering (in terms of natural sunlightexposure) to be accumulated in from about 3 to about 10 days.

[0008] 2. Description of the Prior Art

[0009] U.S. Pat. No. 4,817,447 discloses a weathering chamber usinglamps and sample temperature control using cooling air. Uniform sampleirradiance at accelerated levels of up to 10 suns (within the UVbandwidth) appears attainable.

[0010] A test apparatus incorporating a mirror, which rejects infrared,is disclosed in U.S. Pat. No. 4,012,954. In the '954 patent, convectivecooling air and a conductively cooled substrate are also incorporated.However, although convective cooling is used, the air movement is notused to deliver humidity to the samples during exposure; rather,humidity is provided by floating the sample substrate in a water bath.Further, as in the case of U.S. Pat. No. 4,817,477, the '954 patent usesartificial light sources for exposure of the samples.

[0011] U.S. Pat. No. 3,686,940 discloses a water-cooled cylindricalmirror, which rejects infrared radiation in an ultraviolet testapparatus. In the '940 patent, natural sunlight is not used.

[0012] U.S. Pat. No. 4,627,287 disclose a light resistance testerapparatus that eliminates nonuniformity of the temperature by providinga flow divider in the lower region of a sample-holder setting frame sothat the circulating air can flow through the central part of the testeraround the xenon lamp without contacting the surfaces of samples,thereby substantially eliminating the nonuniformity of temperature dueto such circulating air.

[0013] A solar weathering device with control of sample temperature bycooling air is disclosed in U.S. Pat. No. 4,807,247. While this patentuses natural sunlight, a sample irradiance at accelerated levels of onlyup to 8 suns across the complete solar spectrum is employed.

[0014] U.S. Pat. No. 5,138,892 discloses accelerated light fastnesstesting of materials with xenon lamps and sample temperature controlusing airflow. Sample irradiance at accelerated UV levels of up to 8suns (180 W/m² between 300-400 nm) are attainable. This patent does notutilize natural sunlight in its testing of materials.

[0015] A weather test machine using xenon lamps and sample temperatureand humidity control using airflow is disclosed in U.S. Pat. No.5,646,358. Uniform sample irradiance at accelerated levels up to 1-3suns (within the UV bandwidth) is attainable. This patent does notutilize natural sunlight in its weather test machine.

[0016] U.S. Pat. No. 5,153,780 discloses a dish reflector and method forconcentrating moderate solar flux uniformly on a target plane, said dishhaving stepped reflective surface characterized by a plurality ofring-like segments arranged about a common axis, each segment having aconcave spherical configuration.

[0017] 3. The Need for Capabilities Beyond the Prior Art

[0018] There is a need for devising facilities for ultra-acceleratednatural sunlight exposure testing of materials and devices undercontrolled weathering conditions that include several concurrent levelsof temperature and/or relative humidity at very high levels of naturalsunlight. This need is associated with the desirability to be able topredict the in-service lifetimes of said materials and devices fromcorrelation's derived between such realistically accelerated testresults and those obtained during normal use conditions. Further, thereis a need to conduct these ultra-accelerated exposure tests atirradiance exposure factors of from about 25 to 100 suns, wherein theirradiance is highly uniform. The need to conduct theseultra-accelerated natural sunlight exposure tests of materials anddevices should exclude artificial light sources which invariablyintroduce uncertainties regarding realistic spectral content of theirradiance stress on samples being exposed. For example, the use ofartificial light leads to unrealistic degradation mechanisms and failuremodes of exposed materials caused by low wavelength (<300 nm) photonsthat are not present in terrestrial solar spectra.

SUMMARY OF THE INVENTION

[0019] In light of the drawbacks of the foregoing prior art, a generalobject of the present invention is to provide the unique capability tocarry out ultra-accelerated exposure testing of materials and devicesunder controlled conditions that include several concurrent levels oftemperature and/or relative humidity at very high levels of naturalsunlight, thereby permitting about a year's worth of representativeweathering, in terms of natural sunlight exposure, to be accumulated infrom about 3 to about 10 days.

[0020] A further object of the present invention is to provide ultraaccelerated exposure testing of materials and devices by controllingsample temperatures and humidities and demonstrating that reciprocityrelationships are obeyed (i.e., level of applied accelerated stress doesnot change failure/degradation mechanism).

[0021] A yet further object of the present invention is to provideultra-accelerated exposure testing of materials and devices that allowsmaterials to be subjected to accelerated irradiance exposure factors of25-100× to provide about a year's worth of representative weathering, interms of natural sunlight exposure, to be accumulated in from about 3 toabout 10 days.

[0022] A still further object of the invention is to provide a method ofcarrying out ultra-accelerated exposure testing of materials and devicesutilizing a sample chamber that allows control of temperature andhumidity during light exposure; wherein concentrated sunlight enters thechamber through an appropriate window, which may include quartz.

[0023] A further object yet still of the invention is to provide amethod for carrying out ultra-accelerated exposure testing of materialsand devices utilizing a cold mirror as a filter that reflects theultraviolet/visible (UV/VIS) and transmits the near infrared (NIR) partof the solar spectrum, since the short wavelength (UV) light has beenshown to be the predominant deleterious stress experienced by materialsand devices during outdoor weathering.

[0024] Another object of the present invention is to provide a method ofcarrying out ultra-accelerated exposure testing of materials and devicesunder controlled weathering conditions, wherein conductive cooling ofsample materials is provided by a water cooled substrate on to whichsamples are placed, and convective cooling is provided by blowing moistor dry air over the top surface of the samples, to provide high or lowhumidity to the samples during exposure of redirected concentratedsunlight into the exposure chamber to reduce the thermal load on thesamples.

[0025] The invention is accomplished by the steps of: utilizing a solarconcentrator to obtain elevated levels (25-100×) of concentratedsunlight with a uniform flux profile on the materials or samples beingtested; splitting the solar spectrum into deleteriousultraviolet/visible (UV/VIS) light into the sample chamber; transmittingconcentrated near-infrared (NIR) radiation to minimize undesirablethermal loading of material samples; and further control of temperatureand/or relative humidity experienced by materials samples within theexposure chamber. The solar spectrum is split at a cut-off wavelengthλ_(cutoff) such that UV/VIS consists of wavelengths less than λ_(cutoff)and VIS/NIR consists of wavelengths greater than λ_(cutoff). Variouscombinations of concentrator designs (reflective and refractive),secondary reflectors, secondary concentrators, and turning mirrors canbe used to provide the uniform flux. Additionally, the spectralsplitting can be achieved at various points in the system through theuse of coatings applied to any number of optical elements.

[0026] In terms of the best additional means for facilitating thegeneral effect of ultra-accelerated natural sunlight exposure testing ofmaterials, the facilities are as follows:

[0027] 1) Multi-faceted concentrator design with facets having thefollowing characteristics:

[0028] Hexagonal, circular, rectangular, and triangular shaped facetsarranged in a close packed array;

[0029] Facet centers located on a plane, parabola, sphere or othernon-analytic shape;

[0030] Facet curvature that is flat, spherical, parabolic or aspheric;and

[0031] Facet reflector coatings designed to reflect UV light andtransmit visible and IR, in the following configurations:

[0032] a) Multi-faceted concentrator with geometry and design of facetsto produce uniform flux on a sample chamber located at or near the aimpoint of the facets

[0033] b) Multi-faceted concentrator with secondary reflector designedto deliver uniform flux to the sample chamber located near the center ofthe facet array

[0034] c) Multi-faceted concentrator with secondary concentratordesigned to deliver uniform flux to the sample chamber located near theexit of the secondary

[0035] d) Multi-faceted concentrator with secondary reflector designedto deliver uniform flux to the sample chamber located below thesecondary to allow a horizontal orientation of the sample chamber.

[0036] e) Multi-faceted concentrator with secondary reflector designedto deliver uniform flux to the sample chamber located below a turningmirror placed near the center of the facet array.

[0037] f) Multi-faceted concentrator with secondary reflector designedto deliver uniform flux to the sample chamber below a turning mirrorplaced near the center of the facet array.

[0038] 2) The multi-step concentrator of U.S. Pat. No. 5,153,780 “Methodand Apparatus for Uniformly Concentrating Solar Flux for PV Applicationsusing a reflector coating designed to reflect UV light and transmit VISand NIR in the following configurations:

[0039] a) Multi-step concentrator with geometry and design of steps toproduce uniform flux on a sample chamber located at or near the aimpoint of the various steps

[0040] b) Multi-step concentrator with secondary reflector designed todeliver uniform flux to the sample chamber located near the center ofthe multi-step concentrator

[0041] c) Multi-step concentrator with secondary concentrator designedto deliver uniform flux to the sample chamber located near the exit ofthe secondary

[0042] d) Multi-step concentrator with secondary reflector designed todeliver uniform flux to the sample chamber located below the secondaryto allow a horizontal orientation of the sample chamber,

[0043] e) Multi-step concentrator with secondary reflector designed todeliver uniform flux to the sample chamber located below a turningmirror placed near the center of the multi-step concentrator

[0044] f) Multi-step concentrator with secondary reflector designed todeliver uniform flux to the sample chamber below a turning mirror placednear the center of the multi-step concentrator

[0045] 3) Fresnel lens concentrator/heat mirror configurations that onlypermit the desired spectral range to be transmitted:

[0046] a) with heat mirror positioned above the top surface of the lens

[0047] b) with one or both surfaces of the lens having a heat mirrorcoating

[0048] c) with heat mirror positioned between the lens and the sample

[0049] d) with heat mirror positioned between the lens and sample, butoriented as a relay mirror to reflect the desired wavelengths to aposition perpendicular to the plane of the lens

[0050] e) a two-stage Fresnel lens that interact as paired prisms toprovide spectral selectivity

[0051] f) any of the above configurations combined with a secondaryconcentrator to achieve the desired flux uniformity

[0052] 4) Holographic concentrator in the following configurations:

[0053] a) achieves both spectral splitting and uniform concentration inits fundamental design

[0054] b) provides spectral splitting in its fundamental design and usesa secondary concentrator to achieve the uniform flux

[0055] c) concentrates in its fundamental design and uses a secondaryconcentrator to achieve the uniform flux, but with a cold mirror coatingon the secondary

[0056] d) provides uniform flux in its fundamental design and uses acold mirror to achieve the spectral splitting

[0057] e) concentrates in its fundamental design and uses a secondaryconcentrator to achieve the uniform flux, but with a cold mirror placedbetween the lens and secondary to achieve the spectral splitting

[0058] 5) Use of a 2D or 3D micro lens array to achieve flux uniformityand/or spectral splitting

[0059] 6) An array of Fresnel lens facets can be used to achieve fluxuniformity and in conjunction with a heat mirror or a cold mirror canprovide spectral splitting

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The drawings that are incorporated in and form part of thespecification will illustrate alternative embodiments of the invention,and serve together with the description to explain the principles of theinvention wherein:

[0061]FIG. 1 shows a multi-faceted concentrator design that receivesincident natural sunlight. The design transmits VIS/NIR and reflectsUV/VIS onto a sample exposure plane.

[0062]FIG. 2 shows a multi-faceted design that transmits VIS/NIR andreflects UV/VIS onto a secondary reflector, which in turn reflectsuniformly concentrated natural sunlight onto a sample exposure plane.

[0063]FIG. 3 shows a multi-faceted concentrator design for affectingultra-accelerated natural sunlight exposure testing, in which naturalsunlight is made incident upon a multi-faceted design that transmitsVIS/NIR and reflects UV/VIS through a secondary concentrator and onto asample exposure plane.

[0064]FIG. 4 shows a multi-faceted concentrator design with a secondaryreflector that delivers uniform flux to a sample chamber located belowthe secondary reflector to allow a horizontal orientation of the samplechamber.

[0065]FIG. 5 shows a multi-faceted concentrator with a secondaryreflector designed to deliver uniform flux to a sample exposure plane ina chamber located below a turning mirror.

[0066]FIG. 6 shows a multi-faceted concentrator design that contains areflector coating to reflect the full solar spectrum onto a secondaryreflector that transmits VIS/NIR and reflects UV/VIS onto a sampleexposure plane.

[0067]FIG. 7 shows a multi-faceted concentrator design that reflects thefull solar spectrum onto a secondary reflector that in turn reflectsonly UV/VIS onto a horizontally disposed sample exposure plane.

[0068]FIG. 8 shows a multi-faceted concentrator design that reflects thefull solar spectrum UV/VIS/NIR. The full solar spectrum is reflectedonto a secondary reflector that transmits VIS/NIR and reflects UV/VISonto a turning mirror that reflects the UV/VIS onto a horizontallydisposed sample exposure plane.

[0069]FIG. 9 shows a multi-stepped concentrator design for uniformlyconcentrating solar flux, in which a plural-stepped concentrator havingreflective surfaces is used to reflect UV/VIS onto a sample exposureplane and transmit VIS/NIR. Other combinations of elements can be usedwith the multi-stepped concentrator including a secondary reflector orturning mirror to allow repositioning of the sample exposure chamber.

[0070]FIG. 10 shows a heat mirror positioned above the top surface of aFresnel lens to allow only the desired spectral range to be transmittedand the Fresnel lens is used to uniformly concentrate the UV/VIS.

[0071]FIG. 11 shows another use of the Fresnel lens in which one or bothsurfaces of the Fresnel lens has a heat mirror coating that allows onlythe desired spectral range to be transmitted and the Fresnel lens isused to uniformly concentrates the UV/VIS.

[0072]FIG. 12 shows a Fresnel lens in which a heat mirror is positionedbetween the Fresnel lens and the sample plane to allow only the spectralrange to be transmitted and the Fresnel lens is used to uniformlyconcentrate the UV/VIS.

[0073]FIG. 13 shows a Fresnel lens that provides uniform concentratedlight on a sample exposure plane that is perpendicular to the plane ofthe Fresnel lens and uses a relay minor that performs the desiredspectral splitting and is positioned at an appropriate angle to achieveuniformity.

[0074]FIG. 14 shows a two-stage (double-layer) Fresnel lens arrangementin which the surface geometry is such that the desired concentrateduniformity over the required area in the sample exposure plane isachieved but the surface features of the two arrays (separated bylow-index of refraction media such as air with n=1) interact as pairedprism elements to provide spectral selectivity.

[0075]FIG. 15 shows a refractive means by which the spatial splitting ofwavelengths can be accomplished by using a pair of dispersion prisms toachieve spectral selectivity.

[0076]FIG. 16 takes any of the configurations described in FIGS. 10 to14 above in which a secondary concentrator is incorporated to achievethe desired flux uniformity and/or to reposition the sample exposureplane to a more desirable orientation (i.e., horizontal) during exposuretesting (where the secondary concentrator may also be used to performspectral selectivity, as for example, functioning also as a coldmirror).

[0077]FIG. 17 shows a holographic device that concentrates the solarirradiance and performs the desired spectral splitting and provides fluxuniformity over the required area in a sample exposure plane.

[0078]FIG. 18 shows a holographic device that concentrates the solarirradiance and performs the desired spectral splitting and uses asecondary concentrator to provide flux uniformity over the required areain a sample exposure plane (SEP).

[0079]FIG. 19 shows a holographic device that concentrates the solarirradiance and provides flux uniformity over the required area in asample exposure plane, and uses a cold mirror to achieve the desiredspectral splitting.

[0080]FIG. 20 shows a holographic device that concentrates the solarirradiance and provides flux uniformity over the required area in asample exposure plane, and uses a heat mirror to achieve the desiredspectral splitting.

[0081]FIG. 21 shows a holographic device that concentrates the solarirradiance and uses a secondary concentrator to provide flux uniformityover the required area in a sample exposure plane and also uses thesecondary concentrator to achieve the desired spectral splitting.

[0082]FIG. 22 shows a holographic device that concentrates the solarirradiance and uses a secondary concentrator to provide flux uniformityover the required area in a sample exposure plane and uses a heat mirrorto achieve the desired spectral splitting.

[0083]FIG. 23 utilizes any of the configurations described in FIGS.17-22 above, in which a secondary concentrator is incorporated toachieve the desired flux uniformity and/or to reposition the sampleexposure plane to a more desirable orientation (e.g., horizontal) duringexposure testing.

[0084]FIG. 24 shows as a means for refractively achieving concentratedsolar irradiance and/or spectral splitting and/or flux uniformity with a2-dimensional or 3-dimensional array of microlenses.

[0085]FIG. 25 shows a multi-faceted refractive element MFRE (i.e.,lenses or Fresnel lenses) used in conjunction with a heat mirror.

[0086]FIG. 26 shows a cut-away view of an advanced exposure chamberdesign in accordance with the invention.

[0087]FIGS. 27a, 27 b and 27 c show additional views of the embodimentof the exposure chamber design of FIG. 26.

[0088]FIG. 28 is a perspective view of the system layout of theapparatus of the invention showing the sample chamber interface, via acold mirror, with the HFSF/IRG components.

[0089]FIG. 29 shows the sample exposure chamber detail design thatallows two levels of temperature and two levels of relative humidity tobe maintained during sunlight exposure for the apparatus of theinvention and ability to monitor spatial and spectral uniformity of thesolar beam in situ during sample exposure; wherein:

[0090]FIG. 29a shows a top view of the heating/cooling chamber withsamples in place.

[0091]FIG. 29b shows a top view of the chamber with humidity chamber inplace.

[0092]FIG. 29c is a side view of the heating/cooling chamber.

[0093]FIG. 29d is a side view of the humidity chamber.

Preferred Means for Facilitating Ultra-Accelerated Natural SunlightExposure Testing

[0094] Referring flow to FIG. 1, there is shown a multi-facetedconcentrator design MF that receives incident natural sunlight NS. Themulti-faceted design transmits VIS/NIR and reflects UV/VIS onto a sampleexposure plane SEP in chamber means (not shown) that provide single ormultiple concurrent levels of temperature and/or relative humidity tofacilitate accelerated aging.

[0095] Natural sunlight NS is made incident on yet another multi-facetedMF design as shown in FIG. 2. In this figure, the multi-faceted designtransmits VIS/NIR and reflects UV/VIS onto a secondary reflector SR,which in turn reflects uniformly concentrated natural sunlight onto thesample exposure plane SEP located in chamber means that provide singleor multiple concurrent levels of temperature and/or relative humidity tofacilitate weathering of sample materials.

[0096] A multi-faceted concentrator design for affectingultra-accelerated natural sunlight exposure testing is shown in FIG. 3in which natural sunlight NS is made incident upon a multi-faceteddesign that transmits VIS/NIR and reflects UV/VIS through a secondaryconcentrator SC and onto a sample exposure plane SEP disposed withinchamber means that provide single or multiple concurrent levels oftemperature and/or relative humidity.

[0097] A multi-faceted concentrator MF design configuration with asecondary reflector SR designed to deliver uniform flux to a samplechamber located below the secondary reflector to allow a horizontalorientation of the sample chamber is shown in FIG. 4, in which naturalsunlight NS is made incident upon the multi-faceted concentrator thattransmits VIS/NIR and reflects UV/VIS onto the secondary reflector SR,which in turn, reflects a uniform flux of UV/VIS onto the horizontallydisposed sample exposure plane SEP within chamber means that providesingle or multiple concurrent levels of temperature and/or relativehumidity.

[0098] A multi-faceted concentrator MF with a secondary reflector SRdesigned to deliver uniform flux to a sample exposure plane SEP in achamber located below a turning mirror TM is shown in FIG. 5. In thisfigure, natural sunlight NS is made incident upon MF which transmitsVIS/NIR and reflects UV/VIS onto secondary reflector SR which reflects auniform flux onto a turning mirror TM, that in turn reflects UV/VIS ontoa sample exposure plane SEP in chamber means that provide single ormultiple concurrent levels of temperature and/or relative humidity tocause accelerated weathering.

[0099] A multi-faceted concentrator MF that contains a reflector coatingto reflect the full solar spectrum is shown in FIG. 6. In FIG. 6 naturalsunlight is made incident upon the multi-faceted reflector coating, andthe full spectrum UV/VIS/NIR is reflected onto a secondary reflector SR,which transmits VIS/NIR and reflects UV/VIS onto a sample exposure planeSEP located in chamber means that provide single or multiple concurrentlevels of temperature and/or relative humidity to facilitate acceleratedaging of the test sample.

[0100] A multi-faceted concentrator design MF that reflects the fullsolar spectrum onto a secondary reflector SR that in turn reflects onlyUV/VIS onto a horizontally disposed sample exposure plane SEP is shownin FIG. 7.

[0101]FIG. 8 shows a multi-faceted concentrator design MF that alsoreflects the full solar spectrum UV/VIS/NIR. The UV/VIS/NIR is reflectedonto a secondary reflector SR which transmits VIS/NIR and reflectsUV/VIS onto a turning mirror TM that reflects the UV/VIS onto ahorizontally disposed sample exposure plane SEP located in chamber meansthat provide concurrent levels of temperature and/or relative humidityto facilitate accelerated aging of the sample material.

[0102] In FIG. 9, a multi-stepped concentrator design for uniformlyconcentrating solar flux is shown, in which a plural-steppedconcentrator dish 10 having reflective surfaces comprised of forexample, 5 reflective surface elements, including a hub elementdesignated by n1 and ring-shaped reflective elements n2-n5, liessymmetrically about a common axis A. The reflective elements n1-n5 aredefinable by reference dish RD, an imaginary parabolic dish that sharesa common axis A, as shown. Reference dish RD has a focal length F and atarget plane TP perpendicular to the A axis, at a distance equal to thefocal length F from the vertex V, and the sample exposure plane SEPlocated in chamber means that provide single or multiple concurrentlevels of temperature and/or relative humidity to facilitate acceleratedaging. The multi-step concentrator employs a reflector coating RC thatreflects UV/VIS onto the SEP and transmits VIS/NIR.

[0103] Alternative design configurations to the multi-step concentratorwith geometry and design of facets to produce uniform flux on a samplechamber located at or near the aim point of the facets (as shown in FIG.9), can be: a multi-step concentrator with secondary reflector designedto deliver uniform flux to the sample chamber located near the center ofthe facet array; a multi-step concentrator with secondary concentratordesigned to deliver uniform flux to the sample chamber located near theexit of the secondary concentrator; a multi-step concentrator withsecondary reflector designed to deliver uniform flux to the samplechamber located below the secondary concentrator to allow a horizontalorientation of the sample chamber; and a multi-step concentrator withsecondary reflector designed to deliver uniform flux to the samplechamber below a turning mirror placed near the center near the facetarray.

[0104] Referring now to FIG. 10, it can be seen that uniform,non-concentrated natural sunlight NS is incident on a heat mirror HMwhich reflects VIS/NIR but transmits UV/VIS. The UV/VIS is transmittedto a Fresnel lens FL to permit only the desired spectral range ofuniform concentrated spectrally split natural sunlight D to be incidentupon the sample exposure plane SEP.

[0105] One or both of the surfaces of a Fresnel lens may be providedwith a heat mirror coating HMC that allows the desired spectral range tobe transmitted, as is shown in FIG. 11, where uniform, non-concentratedincident natural sunlight NS is made incident upon a heat mirror coatingHMC on either the top or bottom or both sides of a Fresnel lens FL, sothat UV/VIS is transmitted onto a sample exposure plane SEP.

[0106] Another of the preferred embodiments for facilitatingultra-accelerated natural sunlight exposure testing is by a heat mirrorHM positioned between a Fresnel lens and the sample plane to permit onlythe desired spectral range to be transmitted, as is shown in FIG. 12. InFIG. 12, uniform, non-concentrated incident natural sunlight NS is madeincident to a Fresnel lens FL which transmits a uniformly-concentrated,broad-band spectral range to a heat mirror HM that reflects VIS/NIR, buttransmits UV/VIS onto a sample exposure plane SEP.

[0107] In a further preferred embodiment, as shown in FIG. 13, a Fresnellens FL is designed to provide uniform non-concentrated incidentsunlight NS and transmits the full spectral range onto a cold relaymirror, which in turn transmits VIS/NIR and reflects UV/VIS onto asample exposure plane SEP.

[0108] In the preferred embodiment of FIG. 14, a 2-stage or double layeruniform concentrated UV/VIS Fresnel lens arrangement is used in whichthe surface geometry is such that not only is the desired concentrateduniformity over the required area in the sample exposure plane achievedbut the surface features of the arrays (separated by a low-index ofrefraction media, such as air with n=1) interacts as paired prismelements to provide spectral selectivity. In FIG. 14, uniformnon-concentrated natural sunlight NS is made incident to a firstFresnel/prism array FLA 1 so that the light is spatially separated intodistinct wavelengths (“rainbow”). A masking pattern is then placed on tothe top surface of a second Fresnel prism array FLA 2 to block unwantedwavelengths>λ_(cutoff) (i.e. high VIS and NIR) such that the lightexiting FLA 2 is recombined light with a λ<λ_(cutoff) prior to directingthe re-combined light with the λ<λ_(cutoff) onto a sample exposure planeSEP.

[0109] A pair of dispersion prisms (1 and 2) can be used to achievespectral selectivity in the following manner, as shown by FIG. 15, inwhich there is-first made an input of uniform distribution of the fullsolar spectrum FSS through a first prism to affect spatiallyseparated/distinct wavelengths SSDW on the one hand and to causeadjustable stop blocks of transmitted wavelengths acceleratedλ>λ_(UV/VIS) or λ>λ_(cutoff), and in which prism No. 2 is used tore-construct or homogenize the spatially selected wavelengths from prismNo. 1 to obtain an output uniform distribution of spectrally selectedlight UDSSL with λ<λ_(cutoff), which is then concentrated in a Fresnellens-like manner. In this connection, it should be noted that theadjustable stop blocks can be directly applied to the first surface ofprism No. 2 (as for example by the use of black paint).

[0110] In general, any of the configurations described in FIGS. 10-14,in which a secondary concentrator is incorporated to achieve the desiredflux uniformity and/or to reposition the sample exposure plane to a moredesirable orientation (i.e., horizontal) during exposure testing may besuitable and it should be noted that the secondary concentrator may alsobe used to perform the spectral selectivity, for example, so as to beable to function as a cold mirror as is shown in FIG. 16. In FIG. 16,uniform, non-concentrated natural sunlight NS is made incident upon atracking primary Fresnel lens array FLA, and from which thetransmissions are adjusted with a secondary concentrator SC that adjustswith primary tracking. The secondary concentrator transmits VIS/NIR (asis done with a cold mirror) where upon uniform concentrated UV/VIS isthen reflected onto a fixed horizontal sample exposure plane SEP.

[0111] The specific embodiment of FIG. 17 shows a holographic devicethat concentrates the solar irradiance and performs the desired spectralsplitting and provides flux uniformity over the required area in asample exposure plane. More specifically, in FIG. 17, uniform,non-concentrated natural sunlight NS is made incident upon a holographicdevice HD which directs concentrated UV/VIS onto a sample exposure planeSEP, and the spectrally split VIS/NIR is made to miss the sampleexposure plane.

[0112] In the preferred embodiment of FIG. 18, there is shown aholographic device that concentrates the solar irradiance and performsthe desired spectral splitting and uses a secondary concentrator toprovide flux uniformity over the required area in the sample exposureplane. More specifically, in FIG. 18, uniform non-concentrated naturalsunlight NS is made incident upon a holographic device HD, whichspectrally splits the incident light into a non-uniform concentratedUV/VIS input so that it falls on a secondary concentrator SC to providea uniform concentrated UV/VIS output on the sample exposure plane SEP,and whereby the non-uniform concentrated VIS/NIR is split away from thesecondary concentrator.

[0113] In yet another preferred embodiment, as shown in FIG. 19, aholographic device HD is used to direct uniform, non-concentratednatural sunlight NS, where upon the incident NS is directed through theHD to transmit VIS/NIR onto a cold mirror CM that reflects UV/VIS onto asample exposure plane SEP.

[0114] A still further embodiment of the invention as is shown in FIG.20, which utilizes a holographic device that concentrates the solarirradiance and provides flux uniformity over the required area in asample exposure plane and utilizes a heat mirror to achieve the desiredspectral splitting (UV+low-VIS versus high-VIS+NIR). In particular, theholographic device HD is utilized to direct uniform, non-concentratednatural sunlight NS through a heat minor HM to effect spectral splittingso that, UV/VIS is transmitted onto a sample exposure plane SEP and theVIS/NIR is reflected off of the heat mirror.

[0115] A holographic device HD through which uniform, non-concentratednatural sunlight NS is directed is shown in FIG. 21. In the preferredembodiment of FIG. 21, the holographic device directs the incident NS sothat transmitted VIS/NIR is passed through a secondary concentrator coldmirror SCCM and UV/VIS is reflected from the SCCM onto a sample exposureplane SEP.

[0116] In the specific embodiment shown in FIG. 22, a holographic deviceHD is utilized to direct uniform, non-concentrated natural sunlight NSonto a heat mirror HM that transmits concentrated non-uniform UV/VISflux onto a secondary concentrator SC, which concentrates uniform UV/VISflux onto a sample exposure plane SEP, while the heat mirrorsimultaneously reflects VIS/NIR.

[0117] Any of the facilities shown in the configurations of FIGS. 17-22,in which a secondary concentrator SC is incorporated to achieve thedesired flux uniformity and/or reposition the sample exposure plane to amore desirable orientation (for example, horizontal) during operationcan be used by adjusting the secondary concentrator with primarytracking, as is shown in the specific embodiment of FIG. 23. In FIG. 23,uniform non-concentrated natural sunlight NS is directed through aholographic device HD so that the UV/VIS portion of the NS is reflectedoff of a secondary concentrator SC (and the VIS/NIR portion istransmitted) that is adjusted with primary tracking so as to reflectuniformly concentrated natural sunlight onto a horizontal fixed sampleplane HFSP. VIS/NIR is transmitted by the SC.

[0118] Another means for refractively achieving concentrated solarirradiance and/or spectral splitting and/or flux uniformity is with a2-dimensional or 3-dimensional array of micro lenses. In thisconnection, reference is made to FIG. 24 in which such an array of microlenses is shown in cross section. As can be seen in FIG. 24, a crosssections view of the 2-dimensional or 3-dimensional array of microlenses in which the individual lenses IL is shown. A top view of theindividual micro lenses is also shown.

[0119] Just as multi-faceted reflective elements can be used to achieveuniform concentration, multifaceted refractive elements (i.e., lenses orFresnel lenses) can be used in conjunction with heat mirrors and/or coldmirrors and/or secondary concentrators, as is shown in FIG. 25. In FIG.25, uniform, non-concentrated natural sunlight NS is directed through amulti-faceted array of lenses MFRE onto a heat mirror HM which transmitsUV/VIS onto a sample exposure plane SEP and reflects VIS/NIR. Thismulti-faceted array of lenses may also be substituted for holographicdevices shown in the embodiments of FIGS. 17-23, where heat and/or coldmirror coatings are applied to the lenses or separate elements or areincorporated into secondary concentrators.

[0120]FIG. 26 is a top view of an alternative embodiment of the exposurechamber design, showing a cut-away view. Samples 90 are disposed so thatthey are separated by a chamber divider 91. The chamber divider is inturn separated by an insulation divider 92. In this embodiment, largerheating/cooling ports 93 are disposed below the humidity ports 94.

[0121] As can be seen from the embodiment in FIG. 27, a number ofalternative ways exist for improving the performance and ease of use ofthe sample exposure chamber. For example, baffles may be added withheating and cooling using a circulating bath with an approximate rangeof −20 to 100° C., thereby eliminating the need for individual electriccartridge heaters that give rise to non-uniform sample exposuretemperatures within a given quadrant. The baffles and chambers may bemachined out of one solid block of aluminum and enlarged slightly. Thiswould allow more room for thermocouple wires and insulation and alsoprovide a better seal between chambers. In addition, an insulated,outside shell may be fabricated, that both chambers would rest in. Thisdesign configuration helps keep temperatures constant and makes theassembly solid.

[0122]FIG. 27 is a top view of FIG. 26 minus the samples. FIG. 27b is aview taken along the line A-A of FIG. 27a, showing the quartz coverplate 100, humidity chamber 101, the insulation 102, a heating/coolingchamber with baffles 103, fiber optic guides 104, and an insulated box105, around the chambers.

[0123]FIG. 28 shows the cross-sectional system layout of the IRG 106,cold mirror 107 and sample chamber 108, wherein incident concentratedsunlight ICS is passed through the IRG and uniform sunlight US exits. Animproved chamber was designed and fabricated that allows up to fourreplicate samples of about 2.2 cm×2.2 cm square in size each to beexposed to the same high level of accelerated solar flux at two levelseach of temperature and

[0124] humidity. For example, at a given flux (e.g., 50× suns), sets ofsamples can be simultaneously exposed at Tlow, RHlow, Tlow, Rlhigh;Thigh, RHlow; and Thigh, RH high. This allows a fourfold increase inexperimental throughput at a particular exposure flux.

[0125] A detailed drawing of the sample exposure chamber is shown inFIG. 29. FIG. 29a is a top view of the heating/cooling chamber withsamples S in place, and showing heating/cooling parts HCP. FIG. 29b is atop view of the chamber with the humidity chamber in place. Duringtesting the samples are mechanically attached to the top surface of theheating/cooling chamber to provide good thermal contact. The humiditychamber sits atop the heating/cooling chamber. FIG. 29c is a side viewof the heating/cooling chamber, showing the pathway P for fiber opticprobes and the cross section view of the heaters 109. FIG. 29d is a sideview of the humidity chamber showing the humidity ports HP and thehighly transmissive quartz window 110.

We claim:
 1. A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprise: means for concentrating solar flux uniformly as concentrated uniform reflected light; means for directing said concentrated uniform reflected light, and means for directing said concentrated uniform reflected light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform reflected light comprise: a multi-faceted concentrator comprising facets that receive incident natural sunlight, transmits VIS/NIR and reflects a uniform flux of UV/VIS onto a sample exposure plane located at or near aim points of said facets in chamber means that provide concur-rent levels of temperature and/or relative humidity that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 2. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in chamber means that provide concurrent levels of temperature and/or relative humidity that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.
 3. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: facets that receive incident natural sunlight, transmits VIS/NIR and reflects a uniform flux of UV/VIS through a secondary concentrator and onto a sample exposure plane located near an exit of the secondary concentrator in chamber means that provide concurrent levels of temperature and/or relative humidity that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 4. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary concentrator which delivers a uniform flux of UV/VIS onto a sample exposure plane located below said secondary reflector to allow a horizontal orientation of the sample chamber in which the sample exposure plane is disposed.
 5. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: a facet array that receives incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that reflects a uniform flux of UV/VIS onto a turning mirror located near a center of the facet array; said turning mirror being disposed to reflect said uniform flux of UV/VIS onto a sample exposure plane located in a chamber below said turning mirror.
 6. The apparatus of claim 1 wherein said multi-faceted concentrator array comprises: facets that receive incident natural sunlight, reflects a full spectrum of UV/VIS/NIR onto a secondary reflector that transmits UV/NIR and reflects a uniform flux of UV/VIS onto a sample exposure plane located in chamber means near said multi-faceted concentrator array to provide concurrent levels of temperature and/or relative humidity that allows sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 7. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: facets that receive incident natural sunlight, reflects a full spectrum of UV/VIS/NIR onto a secondary reflector that transmits VIS/NIR and reflects a uniform flux of UV/VIS onto a sample exposure plane located in horizontally disposed chamber means that provide concurrent levels of temperature and/or relative humidity that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 8. The apparatus of claim 1 wherein said multi-faceted concentrator comprises: facets that receive incident natural sunlight, reflects a full spectrum of UV/VIS/NIR onto a secondary reflector that transmits VIS/NIR and reflects a uniform flux of UV/VIS onto a turning mirror that reflects said uniform flux of UV/VIS onto a sample exposure plane located in horizontally disposed chamber means that provide concurrent levels of temperature and/or relative humidity that allow sample materials to be subject to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 9. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform reflected light, and means for directing said concentrated uniform reflected light, and means for directing said concentrated uniform reflected light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform reflected light comprising: i) a multi-stepped concentrator that receives incident natural sunlight, transmits VIS/NIR and reflects a uniform flux of UV/VIS onto a vertically disposed sample exposure plane disposed in chamber means about a common axis of reflective elements of said multi-stepped concentrator to provide concurrent levels of temperature and/or relative humidity that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials. ii) A multi-stepped concentrator that utilizes a secondary reflector and/or turning mirror to reflect UV/VIS onto a sample exposure plane located near the center or below the center of the array.
 10. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light comprising: i) a front surface VIS/NIR reflective coating means to reflect VIS/NIR and transmit UV/VIS. ii) a Fresnel lens means to receive transmitted UV/VIS and transmit a desired spectral range of uniform concentrated spectrally split natural sunlight; and iii) chamber means capable of receiving said desired range of uniform concentrated spectrally split natural sunlight in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 11. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light comprising: i) a Fresnel lens having a heat mirror coating on either its top or bottom or both sides to reflect VIS/NIR and transmit UV/VIS; and ii) chamber means capable of receiving transmitted UV/VIS in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a year's worth of representative weathering of sample materials.
 12. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprising: i) a Fresnel lens that receives incident uniform, non-concentrated natural sunlight and transmits a desired spectral range, a heat mirror means between said Fresnel lens and sample materials that reflects VIS/NIR but transmits UV/VIS; and ii) chamber means capable of receiving directed UV/VIS from said heat mirror means that encloses multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 13. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform reflective light onto a sample materials comprising: i) a Fresnel lens means that receive uniform non-concentrated incident sunlight and transmits a desired spectral range; ii) a cold relay mirror that receives said transmitted desired spectral range and transmits VIS/NIR and reflects UV/VIS; and iii) chamber means capable of receiving uniform accelerated natural sunlight from said cold relay mirror to enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 14. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprising: i) a first Fresnel/prism array that receives incident uniform, non-concentrated natural sunlight and spatially separates same into distinct wavelengths; ii) a second Fresnel/prism array having a masking pattern on its top surface to block unwanted wavelengths>λ_(cutoff) of high VIS and NIR and transmit and UV/VIS; and iii) chamber means capable of receiving said recombined ultra-accelerated natural sunlight in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 15. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprising: i) a first prism array to affect spatially/distinct wavelengths from incident uniform, non-concentrated sunlight and provide adjustable stop blocks of accelerated λ>λ_(UV/VIS) or λ>λ_(cutt-off); ii) a second prism array to reconstruct or homogenize accelerated wavelengths from said first prism array to provide a uniform distribution of spectrally selected light; and iii) chamber means capable of receiving said distribution of spectrally selected light in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 16. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a tracking primary Fresnel lens array that receives incident uniform, non-concentrated natural sunlight; ii) a secondary concentrator that transmits VIS/NIR wavelengths ranges from said tracking primary lens array and reflects UV/VIS; and iii) chamber means capable of receiving reflected UV/VIS in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 17. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic means that receive uniform, non-concentrated natural sunlight and spectrally splits said sunlight into VIS/NIR and directs said UV/VIS into a chamber means; and ii) chamber means capable of receiving UV/VIS in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 18. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic device that receives and concentrates incident uniformity, non-concentrated natural sunlight and spectrally splits said sunlight into VIS/NIR and UV/VIS; and ii) a secondary concentrator that receives said UV/VIS and directs said UV/VIS into a chamber means; and iii) chamber means capable of receiving said UV/VIS in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 19. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform reflective light onto a sample materials comprises: i) a holographic means to receive incident uniform, non-concentrated natural sunlight and transmit the same; ii) a cold mirror that transmits VIS/NIR received from said holographic means and reflects UV/VIS received from said holographic means to a chamber means; and iii) chamber means capable of receiving UV/VIS from said cold mirror into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 20. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic device that receive incident uniform, non-concentrated natural sunlight and spectrally splits said sunlight into a VIS/NIR fraction and a UV/VIS fraction; ii) a heat mirror that reflects the VIS/NIR fraction and transmits the UV/VIS fraction onto a chamber means; and iii) chamber means capable of receiving said UV/VIS fraction from the heat mirrors into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 21. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic device that receives incident uniform, non-concentrated natural sunlight and spectrally splits said sunlight into VIS/NIR and UV/VIS fractions; ii) a secondary concentrator cold mirror that transmits VIS/NIR and reflects UV/VIS onto chamber means; and iii) chamber means capable of receiving reflected UV/VIS from said secondary concentrator cold mirror into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 22. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic device that receives incident uniform, non-concentrated natural sunlight and spectrally splits said sunlight into VIS/NIR and UV/VIS fractions; ii) a secondary concentration that receives and concentrates said UV/VIS fraction; and a heat mirror which reflects said VIS/NIR fraction; and iii) chamber means capable of receiving said UV/VIS fraction from said secondary concentrator into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 23. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a holographic device that receives incident uniform, non-concentrated natural sunlight and reflects said sunlight off of a secondary concentrator that is adjusted with the primary tracking so as to reflect uniform, concentrated ultra-accelerated natural sunlight on a horizontal fixed sample plane; ii) chamber means capable of receiving said uniform concentrated natural sunlight into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials.
 24. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light, and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a 2-dimensional or 3-dimensional array device of micro lenses that receive uniform, non-concentrated natural sunlight and refractively concentrates and/or spectrally splits said sunlight into VIS/NIR and UV/VIS fractions; and ii) a surface means to transmit said VIS/NIR and reflect said UV/VIS; and iii) chamber means capable of receiving refracted UV/VIS into enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials
 25. An apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: means for concentrating solar flux uniformly as concentrated uniform refracted light and means for directing said concentrated uniform refracted light onto sample materials contained in a chamber having means to provide single or multiple concurrent levels of temperature and/or relative humidity, wherein said means for concentrating solar flux uniformly and means for directing concentrated uniform refracted light onto a sample materials comprises: i) a multi-faceted array of lenses device means that receive incident uniform, non-concentrated natural sunlight; ii) a heat mirror means that reflects a VIS/NIR fraction of said sunlight and transmits a UV/VIS fraction of said sunlight; and iii) chamber means capable of receiving said transmitted UV/VIS fraction in enclosed single or multiple concurrent levels of temperature and/or relative humidity providing means to allow sample materials to be subjected to accelerated-irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth of representative weathering of sample materials. 